I did check it today - you guys were right, the tank on the right is also for gasoline with a crossover tube that goes under the engine from one side to the other. The red cap is just a temporary thing they put on to keep the rain out (too bad they didn't do that for the engine). Yes, there is a fuel drain on the right side also (very bottom). Thus, looks like you could fill up from either side, and you could drain from either side also. Tanks are both empty, bone dry with no smell. Bad news is that peering into both tanks I can see they have rust in them, which I'll have to deal with eventually.
Finally, I opened the side panel for the drive and chains, it looks very clean and like new in there - compared to the rest of the unit. Chains seem to be in very good condition, and the gear sprockets don't show much wear. Also, the clutches look to be new or fairly new. The hydraulic fluid looked clean and I could see through it - it had color of maple syrup (or dark honey) and about same consistency; I don't think it was ATF. Is there a way to figure out what it is actually?